An Oregon blogger was recently sued for defamation, for 2.5 million. You can read all about it here.
In Oregon, and I would assume many other places, bloggers who are not employed by an official media establishment are not considered journalists. Therefore, they do not qualify for shield-law protection.
The article will explain what shield-law protection is, along with a more in-depth explanation of what happened to the blogger.
But I think it's important for all bloggers to take heed and pay very close attention to what they post online. These days you never know what can happen. The law is, as they say, the law.